Scotland's Wildlife – an assessment of biodiversity in 20

9 Upland ecosystems
The extent and stature of Scotland’s uplands are distinctive, both in terms of the rugged
landscape character and range of habitats not duplicated elsewhere in the world.
According to the Countryside Survey report for Scotland, published in 2009, over half of
Scotland’s land area (55%) is upland habitat: montane (0.5%); inland rock (1%);
bracken (1.6%); fen, marsh & swamp (3%); dwarf shrub heath (11%); acid grassland
(12%); and bog (26%). Montane and inland rock are insufficiently represented in the
sample to be reported on. The five that are sufficiently represented, in order of
magnitude, are described here.
9.1 Habitat extent
Bracken
Although the bracken plant is natural in Scotland, infestation can degrade habitats like
heather moorland and, being unpalatable, disproportionately reduce the productivity of
hill grazing as it rapidly colonises deeper soils on the most fertile ground. Where
scattered in relatively small patches, bracken is difficult to detect and measure in
sample surveys. Countryside Survey reports only on dense stands, where bracken
exceeds 95% cover. The extent of bracken remained essentially unchanged between
1998 and 2007 (an apparent increase of 8%, from 121,000ha to 131,000ha, was not
statistically significant). The interchange of gains and losses between habitats is
illustrated in Figure 9.1.
Bracken increased significantly in the intermediate uplands and islands, where it was
already most abundant, from 49,000ha in 1998 to 62,000ha in 2007.
Figure 9.1
Change in the extent of bracken broad habitat between 1998 and 2007
Source: Countryside Survey 2007
Note: negative changes (losses) are scaled differently from positive changes (gains)
losses
80% unchanged
gains
5% heath
6% acid grassland
9% other
120000
100000
80000
60000
40000
20000
0
-20000
area (ha)
58